Grain door for a railway car



Aug. 2o, 1957 J. M. GERRARD ETAI- GRAIN DOOR FOR A RAILWAY CAR Filed April 2s, 195s.

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In. '\|l|l .MINI MINII IIIHAHIII.II HHH!"HIHHHHIV All 75a mezz/fors. k/m 'er/"arczj 5, Maak/M055' Aug. 20, 1957 J. M. GERRARD ErAL 2,803,299

GRAIN DOOR FOR A RAILWAY CAR Aug. 20, 1957 J. M. GERRARD ETAL 2,803,299

GRAIN DooR FoR A RAILWAY CAR F1114 April 25, 1953 s sheets-sheet s ufff/bz 57,9055.

United States Patent GRAIN DOOR FOR A RAILWAY CAR John M. Gerrard and Melvin E. Ross, Melrose Park, lll., assignors to A. I. Gerrard & Company, Melrose Park, Ill., a corporation of Illinois Application April 23, 1953, Serial No. 350,544 6 Claims. (Cl. 160-368) The invention relates generally to railway cars and the like, and particularly to grain doors for preventing grain, and the like, from owing through the doorway.

In general, grain doors of the type herein involved are secured in the doorway of the car structure prior to the iilling thereof with grain, and as the usual freight car has two doors, one on each of the car, two grain doors per car are required. While grain doors formed from wood, metal, or other relatively rigid material have been in use over a long period of time, one of the most commonly used doors at the present time is constructed of paper and metal straps or strips which are tensioned across the doorway. Grain doors of the latter type are illustrated in Patent No. 2,116,260, issued on May 30, 1938, to H. Corkran, and Patent No. 2,310,860, issued on February 9, 1943, to J. M. Moon. Both of the grain doors illustrated in these patents utilize a plurality of metal straps which extend across the doorway and are fastened at their ends to the car structure, operative to retain the paper or other material in operative position across the doorway, the metal straps acting primarily in tension.

While grain doors of this type have a number of serious disadvantages, they are quite extensively used. One disadvantage of this type of construction is that the metal straps, being identically positioned with respect to the paper or other sheet material employed and secured at their respective ends to the door frame, the nailing will normally be located at substantially the same points on the door posts or jambs each time a door is secured thereto, resulting in eventual deterioration of the door jamb at these common points. Likewise, as a considerable number of straps are employed, each of which is normally fastened by means of four nails, two at each end of the strap, a large member of nails are required for one grain door. Doors of this type normally utilize over sixty-four nails per door, and as the nails must be accurately positioned to engage the strap ends, care must be taken in the nailing operation, as a result of which the average time required to mount a grain door of the type illustrated in these patents is approximately onehalf hour.

Another disadvantage of this type of structure is that the metal straps must be cut when the door is being opened to release the grain, this normally being accomplished by means of an ax lor hatchet, thus leaving dangling strap ends which preferably must be removed prior to emptying the car as a safety measure to prevent injury to`wrkmen or trainmen. Following the emptying of the car, the remains of the grain door must be removed from the doorway, this normally being accomplished by a claw hammer or pry bar with each nail being individually removed, double-headed nails normally being utilized to facilitate removal. Again, the removal operation is a slow one and oftentimes is accompanied by further damage to the door post or jamb.

The present invention, therefore, has among its objects the production of a grain door, constructed of suit- ICC v able sheet material, such as paper, plastic, or the like, which is so designed that it may be easily installed or removed in a minimum amount of time and which permits the use of random nailing in its enclosure, thus reducing car damage.-

Another object of the invention is the production of such a door which utilizes a minimum amount of metal members thus facilitating disposal following use and which is readily adjustable for diierent sized freight cars and different sized doorways.

A further object of the invention is the production of such a grain door which is so designed that it may be partially mounted, leaving the upper portion of the door ing which the door may be extended to its full height.

A further object of the invention is the production of such a grain door which is provided with novel means4 forming a cross-tier connection between the grain doors on opposite sides of the car structure, whereby the unsupported span of the grain door is substantially halved over previous types of doors.

A further object of the invention is the production of such a grain door, utilizing a cross-tie harness between opposite doors which is so designed that the cross-tie structure is suitably positioned irrespective of the effective width of both the doorway structure and the means for mounting the grain door to the car structure.

A further object of the invention is the production of a grain door having the above advantages, which is relatively simple in construction, inexpensive to manufacture, and eflicient for the purposes intended, and which, at the same time, may be readily packaged in the form of a compact roll for shipping purposes, etc., prior to use, whereby the sheet material comprising the door is not sharply folded and thus subject to weakening by creasing or the like.

Many other objects and advantages of the construction herein shown and described will be obvious to those skilled in the art from the disclosure herein given.

To this end our invention consists in the novel construction, arrangement and combination of parts herein shown and described, and more particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like or corresponding parts:

Fig. 1 is a front elevational view of a car doorway with a grain door embodying the present invention mounted therein;

Fig. 2 is a view similar to Fig. l of the interior side of the mounted grain door, illustrated in Fig. l;

Fig. 3 is a sectional view taken approximately on the line 3 3 of Fig. 2;

Fig. 4 is a sectional view taken approximately on the line 4 4 of Fig. 1;

Fig. 5 is a sectional view taken approximately on the line 5 5 of Fig. 2;

Fig. 6 isa perspective view of the portion of the crosstie harness structure and adjacent portion of the grain door;

Fig. 7 is a sectional view taken approximately on the line 7 7 of Fig. 6;

Fig. 8 is a perspective view of a portion of a grainV door illustrating the laminated construction of the sheet material forming the same;

Fig. 9 is a sectional view taken approximately on the line 9 9 of Fig. 8;

Fig. 10 is a top plan view of a portion of the sheet Fig. 12 is a gure similar to Figs. 10 and 11 of still another modication of the sheet material;

Fig. 13 is a iigure similar to Fig. 2 of another embodimentv ofthe present invention;

Fig. 1.4t is a sectional View taken approximately on the line 1414 of Fig. 13; and

Fig. is a sectional view taken approximately on the line 15'-15 of Fig. 13.

The present invention contemplates a grain door structure, utilizing a laminated' sheet material including a ply of suitable reinforcing strands preferably extending both horizontally and vertically with respect to the sheet material, in combination with a cross-tie harness structure centrally positioned with respect to the doorway span, the harness connectingl the grain doors on opposite sides of the car,` thereby in effect. halving the eifective unsupported span of the grain door and thus materially reducing the load pressures thereon per span. As a result of the particular construction employed, relatively heavy metal straps extending across the doorway are eliminated and instead of requiring a considerable amount of nailing, the present grain door may be readily mounted in the car doorway. by means of considerably less nails which may be driven at random along the mounting strips without any particular alignment with other elements of the door structure.

Referring to the drawings and particularly to Figs. 1 through 5, the reference number 1 indicates generally a grain door structure mounted across the doorway 2 ofa freight car 3 or the like. In the construction illustrated, the car 3 includes side walls 4 and floor 5 with the doorway 2 being defined by posts or jambs 6, the latter normally forming the means upon which the grain door is mounted. The car 3 is also provided with the usual sliding door 7 which is closed following filling of the car.

In the embodiment of the invention illustrated in Figs. l through 5, the grain door 1 includes a sheet of material 8 of a size to extend across the doorway 2 and overlie the posts t6, such sheet preferably being of laminated construction and, as illustrated in Fig. 8, comprising an inner sheet 9, outer sheet 11, and intermediate plyv 12.

which are suitably bonded into a unitary or integral structure.

In the construction illustrated in Fig. 8, the sheets 9 and llmay be formed from a suitable paper, plastic or other material while the intermediate ply 12 may be constructed inthe form of two series of .interwoven strands, the series comprising the. strands 13 extending horizontally across the door, and the strands 14 comprising the other series extending vertically. T he strands 13 and 14 may be of any suitable material having the desired characteristics of flexibility, tensile strength, etc., to achieve the desired results and, in the construction illustrated, the sheets 9 and 11 and intermediate ply 12 are secured together by a suitable adhesive material 15 as, for example, a combination of asphalt and latex, suitable plastics, or the like. may be obtained by constructing the strands 13 and 14 of glass fibers. The fabric formed by such interwoven strands is commonly known as scrim and is commercially procurable.

As illustrated in Figs. 1, 2, and 3, the side edges of the sheet are secured to respective nailing strips or boards 16a and 1611, only one board 16a being illustrated in Fig. 3. The side edges of the sheet Saro wrapped around the respective boards 16a and 16h. in fabricating the door, each of the side edges of the sheet 8 are wrapped around one of the strips or boards and secured thereto by suitable means, such as staples 17, longitudinally spaced therealong. The boards or strips are less in length than the side edges of the sheet 8 so that theupper and lower edge portions of the sheet are relatively flexible compared to the intermediate portions thereof. As the sheet S is wrapped atleast several times We have found that very satisfactory resultsaround the boards or strips and preferably stapled thereto along each layer, the sheet is securely attached to the strip. Extending along the outer face of the sheet 8, as illustrated in Figs. 1, 6, and 8, in parallel relation to the boards 16a and 16h is a reinforcing strip 18 which may be of any suitable material, such as light metal, iberboard, or the like, that illustrated in the drawings comprising a very thin metal strip approximately .01 in thickness, which preferably is securely attached to the sheet 11 by adhesive 19 or the like.

Extending through the sheet S and reinforcing member 18 are a pair of horizontally extending slots, indicated generally by the numerals 21a and 21b of a size to receive suitable strap or tie members 22a and 22b. The ends of the members 22a and 22h are operatively secured to the respective grain doors on opposite sides of the car by respective locking members 23, the latter in the embodiment of. the. invention illustrated comprising a metal. channel member having parallel flanges 24 con: nected by a web 25. The members 23 are providedlwith slots 2da and.26b adapted to register with the slots 21a and 2lb whereby the freeV ends 27 of the straps 22a and 2211 may be passed, through the. sheet 8, reinforcing member 18, and locking members 23. The ends 27 of the straps and the members,v 23 are provided with cooperable means for securing the strap endsin position, such means inthe embodiment of the invention illustrated, comprising rivets, indicated generally by the' numeral 28, carried by the member 23 and'a keyhole shaped opening 29 formed in each strap end, the openings 29 being so. positioned in the strap that the narrow portion 29a thereof is positionedadjacentthe free end of the strap and the. enlarged portion 2911 thereof is positioned adjacent the inner portion ofthe strap.

As illustrated in Figs. 6 and 7, the end 27 of the strap, either prior to or following its insertion through the sheet 8 andmember 23 -is bent transversely toward the adjacent rivet 28 and engaged therewith, the portion 29b of the opening being of a size to permit the head 31- of the rivet to pass therethrough and the narrow portion 29a being of a size to receive the shank portion 32 of the rivet. Thus, following insertion of the rivet through the opening 29, tension on the intermediate portion of the strap will result in engagement of the narrow portion of the opening 29 with the shank of the rivet whereby disengagement is prevented by thev head 31. As illustrated in Figs. 6 and 7, the end 27 of the strap is provided with corrugations or beads 33a andv 33h positioned` adjacent to but spaced from the respective ends of the.

opening 29 with the beads extending inwardly toward.

the web 25 of the member 23 when the strap end isr engaged with the rivet 28. The beads 33a and 33b are of.v

a size to engage the web or base of the member 23 and impart a desired degree of resilience to the portion. of the strap containing the opening 29, and thereby exert sufficient pressure against the head 28. of the rivet to retain the strap in operative engagement with the rivet until suflicient tension has been placed'on the straps as a result of the load of the car to insure retention of the strap in engagement with the rivet. The straps 22a and 22b each preferably are a single piece of material, and as the freight cars normally are either eight feet six inches to nine feet four inches in width between the.

mounted grain doors, additional rivets 28 are provided on the channel member 23 so that an adjustment in the car, the first step isto secure a board 35 to the car, the' board being positioned/on the car floor, as illustrated in Figs. 14and'5. Boards of' this `type are normally7 used with previous types of grain doors, such as those illustrated in the patents heretofore referred to, and usually one inch by six inch undressed boards are ernployed for this purpose. These boards are normally secured to the car structure by two nails driven through each end of the board into the respective door posts. Following this operation, the grain door is positioned in the doorway and one side edge carrying one of the mounting boards 16a or 16b properly positioned with respect to the door post and secured thereto by nails passing through the board into the door post. The grain door is then extended across the doorway, the sheet 8 being tensioned slightly to remove any slack in the sheet 8, following which the associated mounting board is secured to the door post by nails in the same manner as the first board. As illustrated in Figs. 2 and 4, the lower ends of the boards 16a and 16b substantially abut against the lower board 35 and the lower portion of the sheet 8 forms a ap which extends downwardly along the inner face of the board 35 to the oor S with the remaining free portion of the Hap 36 lying on the car door. The ap 36 is secured to the car lloor by a strip 37 of wood or other suitable material, positioned adjacent the longitudinal edge of the flap 36, the latter being wrapped around the strip as clearly illustrated in Fig, 4 which is secured to the floor by nails passing through the respective strips and the two layers of the ap 36. Following this operation, an upper board 38, which normally is of the same dimensions as the board 35, is placed along the top edge of the grain door, as illustrated in Figs. 2 and 4, the board 38, likewise, being secured to the door posts by nails located at each end of the board. Referring to Fig. 4, it will be noted that the board 38 sets substantially on the upper ends of the mounting boards 16a and 16b which, as previously mentioned, do not extend to the upper edge of the sheet 8. The distance from the upper edge of the sheet to the adjacent ends of the boards 16a and 1612 preferably is approximately the width of the board 38, so that the upper edges of the sheet 8 and board 38 are substantially aligned.

Following the erection of the door as just described, the second door on the opposite side of the car is erected in the same manner. It will be noted that random nailing may be employed in mounting the boards 16a and 16b. Consequently, even though a large number of grain doors of this type are successively mounted on the car structure, the nails in successive doors will not always fall in substantially the same locations on the door posts as is the case with grain doors currently in use, so that by utilizing the present invention the life of the car structure is materially increased.

Following erection of the doors in the manner described, the workman may extend the ends of the bands 22a and 22b through the respective door structures and then from the exterior of the car may take the ends of the straps 22a and 22h extending outwardly from one of the grain doors and pass them through the slots 26a and 26h in one of the channel members 23, and engage the strap ends with the selected rivets 28. The operation is then repeated von the grain door on the other side of the door, following which the car is ready for loading.

It will be apparent that as the car is loaded, the grain will tend to belly the sheet outwardly on each side of the channel members 23, with the harness comprising the straps 22a and 22b, and channel members 23 serving to divide the single span of the car doorway into two substantially equal spans, each half the length of the doorway. The general rule followed with respect to the maximum pressures exerted on doors of this type by the loaded grain is normally approximately taken as a ratio of the square ofthe doorway or span. in the effective span, maximum stresses on either span areV approximately one-quarter of the maximum stresses that would be exerted on the door, if only a single span Consequently, by halvwereemployed. The present invention withtlre use o two spans thus eliminates the necessity of utilizing relatively heavy metal straps extending entirely across the doorway, and tests of grain doors embodying the present invention onv actual shipments of grain have clearly proved that a grain door constructed in accordance with the present invention possesses adequate strength for the purposes intended.

It will be appreciated that the stress loads or pressures on the various portions of the grain door are not uniform over the face thereof, so that the maximum pressures will be localized or concentrated at or along certain portions of the door structure. To compensate for such localization of pressures and, therefore, stresses in the grain door, structure, the reinforcing ply 12 between the sheets 9 and 11 of the member 8 may be modied to provide greater 4reinforcement along certain portions of the door than along others. Illustrative constructions are illustrated in Figs. 10, l1, and 12 wherein the strands forming the ply 12 are constructed to provide the desired additional reinforcement along certain portions of the door structure. For example, in the construction illustrated in Fig. l0, the horizontal strands 13a may contain a greater number of bers than the vertical strands 14a whereby the reinforcing ply provides greater Strength across the face of the door than from top to bottom.y It has been determined by test that this construction provides very ecient results even where the total number of horizontal and Vtransverse fibers in the construction illustrated in Fig. 8 wherein the horizontal strands and the vertical strands are of the same size. Thus, in the construction illustrated in Fig. l0, the vertical strands may be of smaller size than the corresponding strands illustrated in Fig. 8 and the horizontal strands correspondingly increased in size.

In the construction illustrated in Fig. l1, the horizontal' f vertical strands 14h, again increasing the strength of the door structure in a horizontal direction. In some cases similar results may be obtained by varying the spacing between the horizontal strands whereby such horizontal strands are spaced closer together at the portions of the door subject to the greatest loads, and spaced farther apart at or along portions of the door which is subject to lesser loads.

Fig. l2 illustrates a construction wherein the strands may extend diagonally with respect to the edges of the sheet, thus tending to provide additional strength adjacent the lower corners of the door structure as the diagonal strands 13C adjacent the lower left hand corner and the strands 14C adjacent the lower right hand corner are operatively connected or secured to the car structure adjacent the floor and the respective door posts, with the span of the individual strands diminishing toward the respective corners of the door structure. In those constructions employing horizontally extending strands, the latter all have substantially the same span between their respective secured ends. It will also be apparent that constructions embodying diagonally extending strands may be designed in the same manner as those employing horizontal strands,- whereby certain strands may be either thicker than others or the spacing between adjacent strands may be varied along different portions of the door structure to provide additional reinforcement along portions of the door structure subject to the greatest load stresses.

As illustrated in Figs. 'l and 2, the reinforcing strip or member 18 may be of a length co-extensive with the vertical dimensions of the sheet 8, such construction being illustrated in Fig. 2, or may extend up above the upper edge of the sheet 8, as illustrated in Fig. l. In the former construction the upper end of the strip may be secured by nails or other means to the board 38; or, in the construction illustrated in Fig. 1, may be extended to the top of the doorway and secured to the car structure.

Either ofl these constructions thus provides a vertically extending anchor for the strip 18 and with it the sheet 8, preventing the latter from. sagging in the centerl thereof and insuring that the channel members 23 and straps 22a and 2217 are held inthe desired vertical positions. The strip 18, if formed of metal, as` previously mentioned, is preferably of very light gauge so that it will readily bend or give with the sheet 8 as the latter is bowed or bellied out under the grain load. Obviously, if the strip 1S were rela-tively rigid material, the edges thereof would tend to chafe or cut into the sheet S, whereby the door structure would ultimately fail. To facilitate installation of the straps 22a vand 22h, the latter preferably are provided with suitable markings 39a and 3912, indicating the correct points at which to bend the strap for the two commonly employed widthsV of freight cars. Thus, the workman mounting the door may readily determine the correct points at which to bend the straps when engaging the latter with the grain doors.

Doors embodying the present invention may be readily installed by the average workman at a rate of approximately seven minutes per door or less than one quarter of the time now required for installation of doors presently 1n use.

To release the grain from the car, the sheet 8 is merely severed at the desired point or points by means of an ax or other tool which will readily cut through the sheets 9 and 11 and inner ply 12; and, following emptying of the car, the boards 3S, 16a and 16h, strip 37, and the lower board may be readily removed with a pry bar or the like. In this connection it will be noted that the boards or strips 16a and 16b, and strip 37 may be readily removed as individual units carrying with them the mounting nails passing therethrough and it is, therefore, not necessary to individually remove each mounting nail as is the case with prior devices utilizing metal straps wherein the nails at each strap end must be individually withdrawn. Consequently, it is not necessary to employ double-headed nails in grain doors constructed in accordance with the present invention.

The embodiment of the invention illustrated in Figs. 13 through l5 is similar in construction to the grain door above-described and functions in substantially the same manner. However, in this embodiment, the wooden nailing :strips are eliminated, strips of fiber board or other suitable material being utilized both for nailing purposes and for central reinforcement. This construction also permits the door to be initially mounted for only a portion of its height thereby permitting loading by loading devices having relatively low discharge spouts, which would be blocked if the door was erected to its full height, in which case such type of loading device could not be employed.

Referring to Figs. 13 through 15, the sheet S is constructed in substantially the same manner as that heretofore described, and secured to each side edge of the sheet are a pair of nailing strips i1 and 4Z constructed of suitable berboard or other material having suicient strength properties for the purposes intended, the strips illustrated being approximately two inches in width and three-sixteenths of an inch thick. The lower strip 41 is of a length to position its upper or top end edge above the upper opening 21!) adapted to receive one of the crosstie straps, and the upper strip 42 is of a length to extend from the top board 38 to a point approximately one and one-half or two inches above the upper end of the strip 41. As clearly illustrated in Fig. 15, the strips i1 and 42 along both edges of the sheet d are stapled or otherwise secured to the sheet S which is first rolled about the strips.

In this construction the central reinforcing strip 43 is likewise composed of suitable tiberboard or the like, as is the mounting strip 44 which is utilized to secure the flap 45 to the car door. With this construction, the lower portion of the door may be erected, leaving the portion above the strips 41 free, whereby the latter may be folded or rotated inwardly, as illustrated in Fig. 14, to

permit the use ofa grain loader having the dischargel spout positionedbelow the full height of the grain door,

the spacing between the strips 41C and 42 merely beingA hand. edge of the sheet S is initially folded around the nailing strips t1 and i2 a greater number of times than is the opposite edge of the sheet about its respective nailing strips. in fabricating this door, the sheet 8 may be rolled about each paii of nailing strips a like number of times and suitably stapled to the strips to form a unitary structure. Following the attachment of the nailing strips to the sheet, the right-hand edge of the sheet is rolled several additional turns about the adjacent nailing strips, thus providing additional material adjacent such edge of the door with the initial dimensions of the sheet 8 being such. that the minimum desired Width of. the door is obtained with the additional material rolled upon the strip. However, where it is desired to adjust the grain door to a greater width, one or more. turns of the sheet 3 may unrolled from the strips 41. and 42 to provide additional width to the door structure. Normally, the amount of additional material provided for adjustment will be about twice the width of the nailing strip 41 and 42 so that, assuming such strips are approximately two inches in width, the width of the door will be adjustable from approximately six feet to six feet, four inches, which is an adequate adjustment to permit the door to be utilized on any of the usual freight car structures. Referring to Fig. l5., it will be noted that the reinforcing strip i3 is offset a slight amount toward the right-hand edge of the door so that when the door is erected, as illust-rated in Fig. 13, in which the door is adjusted to its narrowest width, the strip 43 will be slightly offset, such offset being approximately the width of the nailing strips when the door is adjusted to its narrowest size so that when the door is extended to six feet two inches, the member will be exactly centered on the door structure and when adjusted to its full width of six feet four inches, t'ne strip 4.3 will then be offset a corresponding distance towards the left-hand edge of the door. Thus, irrespective of the adjustment of the width of the door, the member 43 will not be more than vtwo inches off of center. `While this amount of offset is not sufcient to create any overloads on 'the sheet 3 it will be appreciated that if the strip d3 were initially centered for the narrowest width, it would be. possible to have such strip offset four inches or more from center when adjusted to its greatest width, in which case there would be considerable danger of overloading the side of the door having the greatest span, and possible failure of the door.

ln erecting this embodiment of the invention the workman may align and mount the lower left-rand nailing strip di to the adjacent door post by nails driven through the material into such post, following which the righthand edge of the door would be adjusted to the proper width, unrollinD additional material, if necessary, and the right-hand strip i1 nailed to the right-hand door post. The flap 45 may then be secured to the car door by means of the strip and nails driven into the door with the free edge of the flap 45 preferably being rolled around the strip ltd, as illustrated in Fig. 14. In the event that it is desired to till the car before erecting the upper portion of the door, the workman may then temporarily nail the upper board 38 directly above the folded line of the door, as indicated in dotted lines in Fig. 14, so that the board 38 would provide a rest or support for the discharge spout of the loader. Following completion of the loading, the workman would then remove the board 38, nail the two strips 42 in operative position, and secure the board 38 in its normal position illustrated in the drawings. In the event such partial erection is not required, the workman may mount the strips 41 and 42 on the one side of the door and then nail both strips'on the opposite side in substantially the same manner as heretof oredescribed with respect to the constructions illustrated in Fig. l.

^ While the cross-tie harness may be secured to opposite doors in the manner heretofore described, if desired, the workman erecting the door may initially secure the lefthand edge of the door to the adjacent door post, following which he mayinsert the straps through the openings in the sheet 8, reinforcing member and one of the ychannel members 23 locking the strap ends to the latter after which the right-hand edge of the door is attached to the adjacent door post. The door structures herein described have only one edge secured to the car structure, sufciently self-sustaining to readily permit the workman to engage the straps with the door and channel member, thus permitting the workman to attach the cross-tie harness without leaving the car interior. After the rst door has been completely erected, the opposite door may be erected in the same manner or, if desired, the straps may merely be extended through the slots in the sheet 8 and connected with the channel member 23 from the exterior of the door as previously described.

In opening and removing the door, the tie straps 22a and 22b may be readily disengaged from the channel members 23 by merely knocking off the rivets which anchor the strap ends, which operation may be easily accomplished with a hammer or other tool.

In packaging doors constructed in accordance with the present invention two doors would normally be packed together, the preferred method of packaging being to lay one door on a at surface, placing the channel members, tie straps, and nailing strips 44 on the door adjacent one side edge thereof, following which the second door is superimposed on the first door with the flaps 45 at opposite sides of the package members. vlhe oor ap of each door is then wrapped around the adjacent edge of the other door, the flap on the lower door being wrapped around and over the upper door, and the flap on the latter being wrapped around and under the lower door so that both ends of the package thus formed are sealed, following which the assembly is rolled upon an axis extending parallel to the slide edges of the respective doors. With this method of packaging, two doors will form a bundle approximately equalV in length to the intended height or" the door structure and about seven inches in diameter, enabling such package to be very readily handled and transported. In the embodiment of the invention just described, the nails employed preferably are similar to a roofing nail having a relatively large head, and actual tests have clearly demonstrated that the combination of the ber strips and large headed .nails provides a very durable and eicient grain door installation which is capable of withstanding all normal loads and stresses to which it would be subjected when mounted on a freight car.

`It will be apparent from the above description that we have provided a novel grain door structure which is very simple in construction, durable and efficient in use, and easily applied or removed from a freight car structure.

I It will also be noted that with the exception of the straps andlocking channels, the entire door structure is disposable as, for example, by burning.

It will be further noted that we have provided a grain door structure which may be installed in a minimum amount of time, thus materially reducing the labor involved, and which will not injure the freight car struc ture even though a large number of doors are successively mounted and removed therefrom.

It will also be noted that we have produced a grain door structure which may be readily packaged as a very compact bundle, and which is designed to permit desired adjustments to accommodate the door to substantially any general type of freight car to which it may be applied and common types of loading devices.

Having thus described our invention, it is obvious that 10 various immaterial modifications may be made inthe same without departing from the spirit of our invention; hence, we do not wish to be understood as limiting ourselves to the exact form, construction, arrangement, and combination of parts herein shown and described or uses mentioned.

What we claim as new and desire to secure by Letters Patent is:

l. In a grain door for railway cars and the like having oppositely disposed doorways, the combination of a pair of like door structures, each adapted to extend across one of said doorways and comprising a rectangularly shaped, laminated sheet of relatively flexible material including a pair of outer sheets and an intermediate ply of crossed strands of suitable material, said sheets and intermediate ply being bonded together by an adhesive to form a unitary structure, a relatively rigid nailing strip positioned adjacent each side edge of said sheet and extending parallel to the adjacent edge of said sheet, the edge portions of the latter being wrapped around and secured to the respective strips, a lower board positioned on the car oor and extending across each doorway and secured to the adjacent car structure, said door structures each having the nailing strips thereof positioned above said lower board and secured by a plurality of nails to the car structure with said strips extending adjacent to and in parallel relation with the side edges of the doorway, said door structure extending across the doorway with the lower portion of said sheet positioned along the inner face of said lower board and the adjacent portion of the car floor, a nailing strip positioned adjacent the lower free edge of said sheet and secured by nails to the car floor, an upper board extending across each doorway along the inner face of said sheet and secured to the car structure, a vertically extending relatively rigid channel member positioned adjacent the exterior face of each door structure, and horizontally dividing the latter into two approximately equal spans, a cross strap extending between the two opposed door structures, the end portions of said strap extending through respective aligned slots in the door structures, and channel members, and cooperable means on the latter and the strap ends for securing such ends to the respective channel members.

2. In a grain door for railway cars and the like having oppositely disposed doorways, the combination of a pair of like door structures, each adapted to extend across one of said doorways and comprising a rectangularly shaped, laminated sheet of relatively flexible ma'- terial including a pair of outer sheets and an intermediate ply of crossed strands of suitable material, said sheets and intermediate ply being bonded together by a suitable adhesive to form a unitary structure, relatively rigid nailing strips positioned adjacent each side edge of said sheet and extending parallel to the adjacent edge of said sheet, the edge portions of the latter being wrapped around and secured to the respective strips, a lower board positioned on the car oor and extending across each doorway and secured to the adjacent car structure, said door structures each having the nailing strips thereof secured by a plurality of nails to the car structure with said strips extending adjacent to and in parallel relation with the side edges of the doorway, said door structure extending across the doorway with the lower portion of said sheet positioned on the inner face of said lower board and the adjacent portion of the car lloor, a nailing strip positioned adjacent the lower free edge of said sheet, and secured by nails to the car oor, a vertically extending relatively rigid channel member positioned adjacent the exterior face of each door structure, and horizontally dividing the latter into two approximately equal spans, a cross strap extending between the two opposed door structures, the end portions of said strap extending through respective aligned slots in the door structures, and channel members, and cooperable means on'the-latter and the strap a fear doorway and comprising a rectangularlyshaped,

laminated sheet of relatively flexible material including a pair of outer sheets and an intermediate ply of crossed strands of material, said sheets and intermediate ply being bonded together to form a unitary structure, `a pair of relatively rigid nailing strips positioned adjacent each side edge of said sheet with the strips of each pair being longitudinally aligned with one another and extending parallel tothe adjacent edge of said sheet, the edge portions of the latter being wrapped around and secured to the respective pairs of aligned strips, the space between each pair of strips being suflicient to permit bending of the sheet thereat, said door structure having thevnailing strips thereof secured by a plurality of nails to the car structure with said strips extending adjacent to and in parallel relation with the side edges of the doorway, said door structure extending acrossthe doorway with -the lower portion of said sheet positioned `on the adjacent portion of the `ear floor, a nailing strip extending along the lower free edge of said sheet and secured by nails tothe car floor, a vertically extending relatively rigid member positioned adjacent the exterior face of each door structure, and horizontally `dividing the latter into two approximately equal spans, a tie strap extending inwardly from the door structure, the adjacent end portion of said strap extending through the door structures, and cooperable means onv the latter and the adjacent strap end for securing such end to said rigid member, said strap being lvertically disposed between the car iloor and the line of bending of the doo-r structure at the junctures of the respective pairs of nailing strips at the side edges of the door structure.

4. In a grain door for railway cars and the like having oppositely disposed doorways, the combination of a pair of like door structures, each adapted to extend across cne of said doorways and comprising a rectangularly shaped, laminated sheet of relatively exible material including a pair ,of outer sheets and an intermediate ply of crossed strands .of glass iibers, saidsheets and intermediate ply being bonded together by a suitable adhesive to for-m la unitary structure, a pair of relatively rigid nailing strips positioned adjacent each side edge of said sheet with the strips Vof each pairbeing longitudinally aligned with one another and extending parallel to the adjacent edge of said sheet, the edge portions of the latter being wrapped around and secured to the respective pairs of aligned strips, one of said pairs of strips having additional material of said sheet wrapped therearound but not secured thereto, the space between each pair of strips being setlicient to permit bending of the sheet thereat, a lower board positioned on the -car `oor and extending across each doorway and secured to the adjacent car structure, said door structures each having the nailing strips thereof positioned above said lower board and secured by a plurality of nails to the car structure with said strips extending adjacent to and in parallel relation with the side edges of the doorway, said door structure extending across the doorway with the lower portion of said sheet positioned alongithe inner face of said lower` board and the adjacent portion of the car iioor, a nailing strip extending along the lower-free edge of said sheet,thelatter being folded back uponthe upper face of said last-mentioned nailing strip, andsecured by nails passing through the strip onto the car floor, an upper board extending across each doorway alongthe inner -faceof said sheet and secured to the car structure,fsaid upper board overlying the upper portion `of said door structure, a vertically extending relatively rigid channel member positioned `adjacent the exteriorY face yof each door structure and horizontally dividing .the latter into two approximately equal spans, a relatively flexible reinforcing strip interposed between each channel member and the face of the adjacent door structure, said reinforcing strip being seoured to 'and carried by said door structure, a pair of cross straps extending between the two opposeddoor structures, the end portions of said straps extending through respective aligned slots in the door structures, reinforcing strips, and channel members, and cooperable means onthe latter `and lthe strap ends for securing such ends to the respective channel members, said straps being vertically disposed `one above the other with the upper straps being positioned below the line of bending of the -door structure at the junctures of the respective pairs of nailing strips adjacent the side edges of the door structure.

5. A grain door as defined in claim 4, wherein the cooperable rneans for securing Veach of `the strap ends to the respective channel members comprises a headed rivet carried bythe channel member and a keyhole-shaped opening in the strap end, the narrow portionof such opening being positioned adjacent the free -end of the strap and of a size to engage and be retained by the rivet head, and

the larger portion of said opening being of a size to pass over the rivet head.

`6. A grain door as defined in claim 4, wherein the cooperable Ameans for securing each of the strap ends to the respective channel members comprises a headed rivet car-v ried by the. channel member and a keyhole-shaped opening in the strap end, the narrow portion of such opening being positioned adjacent the free end of the strap and of a size to engage and be retained by the rivet head, and the larger portion of said'opening being ofa size to pass over the rivet head, said channel members eachy having a pair of .rivets for each strap end, each pair of rivets being vertically 'spaced and yproviding means for selectively Avarying the eifective length of said cross straps.

References Cited in the file of this patent UNITED STATES PATENTS 1,384,137 Lecoutre July 31, 1921 2,073,894 Wood Mar. 16, 1937 2,116,260 Corkran May 3, 1938 2,203,107 Schmitz June 4, 1940 2,310,860' Moon Feb. 9, 1943 2,361,081 Brandon Oct. 24, 1944 2,428,325 Collins Sept. 30, 1947 2,561,781 Bruce July 24, 1951 2,575,666 Knudson Nov. 20, 1951 2,581,991 Weiss Jan. 8, 1952 2,646,117 Hodgins July 2l, 1953 

